Although many published studies on the extraction of phenoliccompounds from mangosteen using ultrasound-assisted methodsare available, i.e., including quantitative and qualitative determina-tion of xanthones (Ji et al., 2007), fast screening and fractionationof major xanthones (Destandau et al., 2009), and the effects ofdrying methods on assay and antioxidant activity of xanthones(Suvarnakuta et al., 2011), the effect of ultrasound sonication timeand amplitude on total phenolic and anthocyanin yield of man-gosteen has not been reported. The objective of this study wasto optimize the extraction yield of total monomeric anthocyanin(TMA) and total phenolic content (TPC) from mangosteen hullby varying the amplitude and sonication time of a direct ultra-sonic treatment using a probe. The best ultrasonic probe conditionswere compared with an indirect application of ultrasonic treatmentusing a bath system.